A population of bed bugs has invaded Building A. A student sampled this populati

Question

A population of bed bugs has invaded Building A. A student sampled this population and estimated the following phenotypic frequencies (which were caused by a single gene with two alleles: B and b; you don’t want to know how this undergrad determined the phenotypes of these bed bugs in this population).

i. 11% aggressive blood suckers (BB)

ii. 26% moderate blood suckers (Bb)

iii. 63% weak blood suckers (bb)

If this population were to reach Hardy-Weinberg equilibrium in one generation, what would the phenotypic frequencies be in that new generation? Application of an insecticide throughout Building A differentially impacts these three genotypic classes. The fitness coefficients in the presence of insecticide are: wBB = 0.9; wBb = 0.5; and wbb = 0.1. What would be the expected phenotypic ratios of bed bugs in the next generation following insecticide treatment? Do you think this application of insecticide should be continued or terminated?

Please answer ALL parts of the question and I will be sure to "thumbs up" your response! Thank you!

Explanation / Answer

The phenotypic frequencies are:

11% of aggressive blood suckers (BB) is 11% of 1 = 0.11

26% of moderate blood suckers (Bb) is 26 % of 1 = 0.26

63% weak blood suckers (bb) is 63 % of 1 = 0.63

If a population is not evolving, the frequencies remain same for remaining generations.

For next generation, the allele frequency will be:

B = 0.11 + (0.26/2) = 0.24

b = 0.63 + (0.26/2) = 0.76

The fitness coefficients after the impact of insecticide ar0.76e given as

wBB = 0.9; wBb = 0.5; and wbb = 0.1

Fitness seems to be good for wBB when compared with heterozygous (wBb) and homozygous recessive (wbb).

The phenotypic ratios for these coefficients will be 0.9 : 0.5 : 0.1

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.